Apparently they notified sellers, but not the rest of the world. AVN picked up on it, though.
eBay Bans Sale of Adult Items, Effective June 15 Onward
According to AVN, eBay sent out a notice to sellers in its Adult Only section stating that the section will close on June 15. All items that meet the site's definition of sexually explicit materials will be removed, and the sale of these items will henceforth be prohibited.
The auction website's new policy places a ban on items that contain explicit sexual material or show 'provocative sexual poses, genitalia, or sexual activity.' This includes anime, comics, books, films, animation, manga, etc."
I checked, and it's true. According to their page help/policies/prohibited-restricted-items/adult-items-policy:
Starting June 15 and effective July 15, 2021, the Adult Only category will no longer be available for new listings on the U.S. site.
Items in the following categories are no longer permitted on eBay:
Sexually explicit Adult Only DVDs & movies
Sexually explicit Adult Only Magazines
Sexually explicit Adult Only Video Games
Sexually explicit Adult Only Domain Names
Sexually explicit Other Adult Only
Sexually explicit Adult Only Collectibles on Blu-Ray, DVD and Film, LaserDisc, VHS, Other Adult Movie Formats, VCD, SVCD, VHS Non-US (PAL)
Oh! And "Male erections, even if the model is clothed" is considered to be nudity. Wow, I've been a nude model for years and never even knew it!